White light confocal optical measurement devices are known as devices used for examining the surface topography of a measurement object. This kind of optical measurement device includes a light source generating illumination light including a plurality of wavelength components, an optical system configured to introduce an axial chromatic aberration into the illumination light from the light source, a light receiving unit configured to separate the reflection light received from an optical system into wavelength components and to receive the light having the wavelength components, and a light guide optically connecting the light source, the optical system, and the light receiving unit. For instance, Japanese Patent Application Publication No. 2012-208102 discloses a confocal measurement device that uses confocal optics for contactless measurement of the displacement of a measurement object.